If the amount of prolapse is significant, there may be a heart murmur (caused by the valve leaflets snapping backwards with ventricular contraction) and/or by incomplete closure of the valve with backward flow of blood across the mitral valve (mitral regurgitation or insufficiency) into the left atrium.

Mitral regurgitation is functionally insignificant unless it progresses to moderate to severe insufficiency resulting in left atrial enlargement, pulmonary hypertension, arrhythmias and reduced cardiac output. Most mitral insufficiency with mitral valve prolapse is mild.

Though Mitral Valve Prolapse is usually not serious, it may be accompanied by various minor symptoms, such as shortness of breath, tiredness, heart palpitations, chest pains, dizziness, headaches, and insomnia. The anomaly increases the risk of infective endocarditis (infection of the interior lining and/or the valves of the heart).